Simple non-polarizing high pass filter
J S Seeley
Applied Optics, Vol 24, No 6, Pages 742-744 (1985)
Non-polarizing edge filters have recently become important to separate those IR gas bands used in atmospheric sensing into their P and R branches, namely, the v2 of C02 at a 15µm wavelength. Whereas Thelen has developed all necessary principles for the entire class of non-polarizing filters it remains difficult to substitute either refractive indices (such as infrared) into a visible-region design or assess the effect on consequent performance.